The present invention relates to printers, and more specifically, to apparatus and methods for printing a metallic layer and a regular color layer.
Thermal printers are used for printing various documents including personal identification cards. Typically, these identification cards have images on their surfaces printed in various colors. Some cards have images printed in metallic color.
In the prior art, there are thermal printers that print on a printing medium in regular colors such as cyan, magenta, yellow, and black and white. In order to print a background layer on the printing medium, a separate pre-printing process for applying a metallic layer on the medium is necessary. However, the application of the metallic layer poses some problems. For example, the metallic printing prior to the regular color printing inevitably incurs some lead time between the two printing steps. Furthermore, it is difficult to keep surfaces printed in metallic colors clean until the time when the regular color printing is performed on the metallic layer.
In view of these and other issues, it would be desirable to have a technique allowing a thermal transfer printer to print in metallic colors and regular colors efficiently and inexpensively.
According to various embodiments of the present invention, a thermal transfer printer includes a roller printing section for transferring metallic ink to a printing medium as a background layer, and a thermal transfer printing section for printing images by transferring regular color ink to the top of the background layer. Thus, the embodiments are capable of efficiently transferring a metallic ink layer to the whole area of a printing medium, and then transferring images using regular color ink on the metallic ink layer.
In some embodiments, the roller printing section includes a transfer roller and a first platen. The transfer roller is operable to heat metallic ink on a metallic ink film for transfer of metallic ink from a metallic ink film to a printing medium. The transfer roller presses the metallic ink film and the printing medium against the first platen. The thermal transfer printing section is operable to heat the regular color ink for transfer the regular color ink from a regular color ink film to the printing medium. The thermal transfer printing section presses the regular color ink film and the printing medium against a second platen.
In some specific embodiments, the thermal transfer printing section includes an intermediate transfer film, a print head, and an intermediate transfer roller. The print head has a plurality of resistance heating elements for transfer of the regular color ink from the regular color ink film to the intermediate transfer film. The intermediate transfer roller is operable to heat the regular color ink on the intermediate transfer film for transfer of the regular color ink from the intermediate transfer film to the printing medium.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.